Final answer:
The physical examination findings are indicative of hyperkalemia, a condition with elevated potassium blood levels that can lead to skeletal muscle weakness, nervous system impairment, and dangerous cardiac dysrhythmias.
Step-by-step explanation:
The symptoms described, such as bilateral muscle weakness that begins in the quadriceps and ascends to respiratory muscles, alongside abdominal distention, decreased bowel sounds, constipation, and cardiac dysrhythmias, particularly when there are signs of digoxin toxicity at normal digoxin levels, suggest the condition known as hyperkalemia. Hyperkalemia is characterized by an elevated potassium blood level, which can impair the function of skeletal muscles, the nervous system, and the heart. This condition can result in symptoms such as difficulty in muscle movement, cardiovascular abnormalities, and, in severe cases, may affect motor coordination, breathing, and heart function due to the effects on repolarization of the cell membrane, potentially leading to fatal outcomes if untreated.